This invention relates to a composite cylindrical roller bearing having both cylindrical thrust rollers and radial rollers, and more particularly to a composite cylindrical roller bearing which is used as a bearing for a cutter head of a tunnel excavating machine or a bearing for a turn- table of a very large scaled building machine.
One of such composite cylindrical roller bearings which are known is shown in FIG. 4. In this bearing, an outer ring 101 thereof is provided with an annular recess in its inner peripheral surface and with axially through holes 105 at its outer peripheral portion, and is fixed to a static member (not shown) by means of bolts (not shown) to be inserted into the holes 105. On the other hand, an inner ring 106 located inside of the outer ring has an annular projection to be fitted in the recess of the outer ring on its outer peripheral surface and also has a driving gear 107 on its inner peripheral surface 106a. The inner ring 106 is screwed on a table (not shown), so that a lower surface 106b of the inner ring is fixed to the table by means of bolts to be fitted in screw holes 117 formed therein.
There are provided a retainer 111 and thrust rollers 114 held by the retainer 111 at a portion defined by a lower surface 109b of the projection of the inner ring 106 and a surface 109a, of the outer ring, facing the surface 109b. Similarly, there are provided a retainer 112 and thrust rollers 115 held by the retainer 112 at a portion defined by an upper surface 110b of the projection of the inner ring 106 and another surface 110a, of the outer ring 101, facing the surface 110b. On the other hand, radial rollers 119 held by a further retainer 118 are disposed at a portion defined by an outer peripheral surface 116b of the projection of the inner ring 106 and a bottom surface 116a of the recess of the outer ring 101.
The inner ring is rotated inside the fixed outer ring 101 along with the table fixed thereto by a rotation force which is externally applied through the driving gear 107.
Seals 122 and 123 are retained by respective annular seal holders 120 and 121 which are respectively fixed to the outer ring 101 and inner ring 106 by bolts 125 and 126.
The outer ring 101 is composed of upper and lower outer ring portion 102 and 103 and is divided into those two pieces in the dismantling.
By the way, a recent trend toward a further increase in size in the large-sized tunnel excavating machines and building machines requires further scaling-up of actually large-sized bearings.
The above described prior art composite cylindrical roller bearing is composed of the upper outer ring portion 102, lower outer ring portion 103, inner ring 106 and retainers 111, 112 and 118, each of which components is formed of an undivisible piece, so that those members are very big and heavy, and this causes difficulty in transporting and repairing. Furthermore, there is a serious problem that size and weight of such bearing components are limited from the point of view of treatment convenience, and this makes it impossible to produce bearings of extraordinarily superlarge size.